Let me preface my comments by saying I used to be a C programmer and I still have scars from it.

I was surprised that you didn't include more details about the numbers.What is the range for the integers? Are the floats binary floating point or decimal floating point? But maybe that is just the scars from C talking.

I was also surprised that you didn't mention how to add comments in this chapter or in chapter 3. For Ruby programmers, it is obvious that it is "#". As a C / C++ / C# / JavaScript programmer, I had to Google it. Is there an Elixir paradigm to avoid comments in favor of self documenting code?